Worldtime system is a display of all 24 time zones on the cardan of a watch.
This system joins a specific display on a bezel at the level of the dial or the watch case of the watch to a specific mechanism which can make the whole move of a twenty-fourth of turn by pressure on a pusher or simply by adjusting the bezel.
This system has the great advantage of showing all the time zones operating by difference of 60 minutes, which represents almost all the time zones. This mechanism was invented by Louis Cottier who then marketed it to companies such as Patek Philippe, Rolex or Vacheron Constantin.
The patent for the invention has been in the public domain for several decades and this system has since been used by several houses.